Improve token management logic

src/tokens.nim

@@ -57,7 +57,7 @@ template expired(token: Token): untyped =
     token.lastUse < time - maxLastUse
 
 template isLimited(token: Token): untyped =
-  token == nil or (token.remaining <= 1 and token.reset > getTime()) or
+  token == nil or (token.remaining <= 5 and token.reset > getTime()) or
     token.expired
 
 proc release*(token: Token; invalid=false) =
@@ -79,8 +79,6 @@ proc getToken*(): Future[Token] {.async.} =
   if result == nil:
     raise rateLimitError()
 
-  dec result.remaining
-
 proc poolTokens*(amount: int) {.async.} =
   var futs: seq[Future[Token]]
   for i in 0 ..< amount: